Neverwinter Nights: Infinite Dungeons

The module is set in Forgotten Realms' Undermountain of Waterdeep, already visited in Hordes of the Underdark expansion. The game is a dungeon-crawler in style of Dungeon Siege featuring D&D rules. The story follows character(s) as they enter Undermountain in order to defeat its ruler, mad mage Halaster and his six powerful generals. A boy named Timmy helps the players while they are resting outside the dungeons, near the underground entrance to Undermountain.

Source: Wikipedia, "Neverwinter Nights: Infinite Dungeons (module)", available under the CC-BY-SA License.